Method of incorporating metal plates in panels



Feb. 11, 1941. LE ROY H. DEY

METHOD OF INCORPORATING METAL PLATES IN PANELS Filed May 9, 1938 lefigyH Dqy Patented Feb. ll, 33%

METHOD or INCORPORATING METAL PLATES IN PANELS 1 ('Ilaim.

The present invention relates to the manuracture of insulating panelsembodying spaced metallic plates which extend lengthwise through thepanels and project from the ends thereof. The

panel and metal plate assembly is particularly adapted for use as aradiator of high frequency electric energy for the purpose ofilluminating gas i'illed display tubes which are placed adjacent to thepanel.

I am aware of course that it is not broadly new to mold metallic devicesin the form of plates or rods in an insulating compound such as thesynthetic resin compound sold under the trade name of Bakelite. Themolding of such materials, however, requires the making of dies and theexpenditure of a considerable sum of money to produce a simple sheetmaterial. Furthermore, it is' desirable to have the additional strengthand freedom from cracking that is obtainable from a plurality oflaminations.

The present invention contemplates, therefore, a method of producingpanels having inserts of metal from a plurality of paper sheets whichhave been impregnated with a suitable insulating material such as thesynthetic resins.

The features and advantages of the invention will appear more fully asthe description proceeds, reference being had to the accompanyingdrawing wherein a preferred embodiment of the invention is disclosed. Itis to be understood, however, that the description and drawing areillustrated only, and are not to be taken as limiting the invention,except insofar as it is limited by the claim.

In the drawing, Fig. 1 is a perspective view of a panel unit constructedin accordance with the present invention;

Fig. 2 is a sectional view taken on the line 2 -2 of Fig, 1,

Fig. 3 is a perspective View showing the manner in which the panel isbent up before being pressed into final form, and

Fig. 4 illustrates the compression of a panel.

Referring now to the drawing, the present invention concerns itself withthe construction of a panel ii such as is shown in Fig. 1, wherein twostrips 6 and l of a metal having high conductivity, such as copper, areimbedded in a surrounding medium of insulating material. The metalstrips project from one end of the panel to provide for their attachmentto a source of current. They may, however, terminate short of theopposite ends of the panel so as to be completely enclosed within theinsulating material except at the point where it is desired to connectthem to the source of energy.

In order to obtain the advantages of enclosing the metal strips ininsulating panels without the disadvantages of high cost of moldedpanels utilizing synthetic resins such as Bakelite, I endeavored toobtain such materials with the metal plates inserted from themanufacturers engaged in the business of producing sheet materials byimpregnating paper and similar fibrous bases with the synthetic resinsand binding the sheets to gether by pressure. I was informed that themetal could not be incorporated due to the fact that the sheet materialand the metal would not combine underv pressure so as to stick together.

I have devised a method whereby the metal and impregnated sheets may becombined under pressure so as to adhere together and produce what is infact a solid sheet made up of a multiplicity of laminations of paper andsimilar fibrous materials impregnated with a synthetic resin binder suchas Bakelite. The method consists in mounting the metal plates betweentwo outside groups of impregnated sheets of paper, which are adapted,when compressed, to give the requisite thickness over the metal plates.As a simple example of the way in which the method is carried out, Ifirst lay the metal strips upon a stack of the requisite number ofimpregnated paper sheets, dipping the metal strips in a synthetic resinvarnish such as that sold by the Bakelite Corporation as Bakelite CementNo. 6052. The metal strips are thus stuck to the top sheet of theimpregnated sheets by the varnish. I then place a sufiicient number offiller sheets between the metal strips and between the edges of thepanel and the metal strips to build up, when compressed, a thicknessapproximately equal to that of the metal strip itself. The spacer sheetsare spaced slightly from the adjacent edges of the metal strips to allowfor a certain amount of spreading and expansion which takes place uponpressure being applied for pressing the sheets together. A number ofsheets equal to the sheets beneath the metal plates are next appliedover the spacer sheets. Then the pressure and heat are applied in a hotpress so as to compress the entire assembly down until the thickness ofthe spacer sheets is no greater than the thickness of the metal strips.The synthetic resin impregnation of the paper causes the several layersto become united so that they appear to be a single panel or sheet.Furthermore, the layers adjacent to the metal strips adhere directlythereto so that the panel may be handled and bent without separationoccurring between the metal strips and their covering.

Owing to the fact that it is quite difficult to match the exactthickness of the metal strips with a definite number of layers of theimpregnated paper, there may be some slight irregularity in thickness.It appears, however, that the compression of the material is notadversely afiected by having slightly too little an amount of fillersheets between the metal strips. In Fig. 2 I have shown, in somewhatexaggerated form, the result of having too few filler sheets between themetal strips. The result is a slight bulge indicated at 8 and 9 onopposite sides of the metal strips.

In Fig. 3 the bottom impregnated sheets are shown at Ill, the fillersheets are shown at H, l2 and I3, and the top sheets are shown at M. Thespaces indicated at 15 and H5 at opposite edges of the strips 6 and 1are to allow for any lateral expansion or spreading of the metal strips6 and 1 and the filler sheets under the pressure to which the filler issubjected. In Fig. t the entire assembly is shown between upper andlower heated press-heads l1 and I8.

From the above description it is believed that the nature of the presentinvention will be clear to those skilled in this art. Having thusdescribed my invention, what I claim as new and desire to secure byLetters Patent is:

A method of incorporating metal plates in insulating panels made up of aplurality of laminations of fibrous material impregnated with asynthetic resin binder, said method comprising the coating of the metalplates directly with a varnish and then adhering the metal to a stack ofimpregnated laminations, placing impregnated filler sheets adjacent tobut slightly spaced from the edges of said metal plate, covering thefiller sheets and plate with a second stack of impregnated laminationsand heating and compressing the assembly to a unitary sheet.

LE ROY H. DEY.

